Research Article

Substrate-engaged 26S proteasome structures reveal mechanisms for ATP-hydrolysis–driven translocation

See allHide authors and affiliations

Science  30 Nov 2018:
Vol. 362, Issue 6418, eaav0725
DOI: 10.1126/science.aav0725

You are currently viewing the editor's summary.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Molecular-motor coordination

The proteasome is a cytosolic molecular machine that recognizes and degrades unneeded or damaged proteins that have been tagged with ubiquitin. A heterohexameric adenosine triphosphatase motor pulls the substrate into the proteolytic chamber, while at the same time, a protein located at the entrance of this motor removes the ubiquitin. De la Peña et al. trapped the substrate inside the motor by inhibiting removal of ubiquitin. This allowed them to determine cryo–electron microscopy structures in the presence of substrate and adenosine triphosphate (ATP). The findings distinguish three sequential conformational states that show how ATP binding, hydrolysis, and phosphate release are coordinated between the six subunits of the motor to cause the conformational changes that translocate the substrate through the proteasome.

Science, this issue p. eaav0725